Instituto de Investigaciones Fisicoquıímicas, Teóricas y Aplicadas (INIFTA), FCE, Universidad Nacional de La Plata - CONICET, Sucursal 4 Casilla de Correo 16 (1900), La Plata, Argentina.
Small. 2012 Feb 6;8(3):468-73. doi: 10.1002/smll.201101293. Epub 2011 Dec 23.
Polyvinylpyrollidone (PVP)-capped platinum nanoparticles (NPs) are found to change shape from spherical to flat when deposited on mesoporous silica substrates (SBA-15). Transmission electron microscopy (TEM), small-angle X-ray scattering (SAXS), and extended X-ray absorption fine structure (EXAFS) analyses are used in these studies. The SAXS results indicate that, after deposition, the 2 nm NPs have an average gyration radius 22% larger than in solution, while the EXAFS measurements indicate a decrease in first neighbor co-ordination number from 9.3 to 7.4. The deformation of these small capped NPs is attributed to interactions with the surface of the SBA-15 support, as evidenced by X-ray absorption near-edge structure (XANES).
聚乙烯吡咯烷酮（PVP）封端的铂纳米粒子（NPs）在沉积到介孔硅载体（SBA-15）上时，其形状从球形变为扁平。在这些研究中使用了透射电子显微镜（TEM）、小角 X 射线散射（SAXS）和扩展 X 射线吸收精细结构（EXAFS）分析。SAXS 结果表明，沉积后，2nm 的 NPs 的回转半径比在溶液中平均增加了 22%，而 EXAFS 测量表明第一近邻配位数从 9.3 减少到 7.4。这些小的封端 NPs 的变形归因于与 SBA-15 载体表面的相互作用，这可以通过 X 射线吸收近边结构（XANES）来证明。
